In Elway's eyes, Manning has just begun his feel-good swan song -- but history is not a friend, even for a player as special as Peyton.

The average age of Super Bowl-winning quarterbacks is 29.9, and only three starting passers have won a title after 35. Every one of them are legendary names.

Let's take a gander:

1. John Unitas was 37 when the Baltimore Colts won Super Bowl V over the Cowboys. Unitas was injured mid-game and relieved by Earl Morrall, who pushed the Colts through an error-filled affair (both teams combined for nine turnovers). Morrall himself was 36, a warrior/wanderer who played 21 seasons for six teams.

2. Jim Plunkett was 33 when he replaced Dan Pastorini during the 1980 season and led the Raiders to victory in Super Bowl XV. Three years later, a 36-year-old Plunkett came off the bench -- this time replacing Mark Wilson -- to win Super Bowl XVII (with a bow to Marcus Allen).

3. Roger Staubach nearly earned membership to this club, winning a second Super Bowl title with the Cowboys at 35, just days before turning 36. The following season, he lost Super Bowl XIII.

4. Elway took a beating in Super Bowls XXI, XXII and XXIV -- when he was 26, 27 and 29 -- but returned at a wise, old 37 years to beat Brett Favre and the Packers in Super Bowl XXXII. Elway never blew you away with the box score. He was 12-for-22 against the Packers, but what's etched in the mind is Elway's gritty, third-down run -- complete with helicopter spin -- that continued Denver's game-winning drive in heroic fashion. One year later, against the Falcons, Elway sizzled, throwing for 336 yards in his final NFL performance.

Elwayâs career arc illuminates a point that Tim Kawakami of Bay Area News Group raised earlier this month: Quarterbacks win Super Bowls early in their career or late, but not both.

Manning, if anyone, is the quarterback to buck the trend -- having won his first at age 30 -- but it's not a given he'll get back to the show. History says this will be a challenge.